This invention relates generally to a clip-on accessory having a pair of filter lenses which register with a pair of optical lenses in eyeglasses when the clip-on accessory is mounted on the frame of the eyeglasses. More particularly, the invention resides in a clip for a clip-on accessory which is anchored on the margin of a filter lens and includes a hook which engages this lens to resist dislodgment of the clip.
A conventional pair of eyeglasses is provided with optical lenses which are prescribed for the wearer of the eyeglasses to correct for visual eye defects. These optical lenses are usually fitted into a metal or plastic frame to which temple pieces are hinged. A wearer of prescription eyeglasses may on occasion find it necessary to protect his eyes from harmful radiation, such as intense rays emanating from the sun, strong light emanating from a welding arc or from a laser beam instrument.
The wearer therefore requires radiation protection glasses having filter lenses which filter out the radiant energy for which the glasses are designed. Thus in the case of sunglasses the filter lenses may simply be formed by a smoked lens, while for other types of radiant energy, the filter lenses must be coated or otherwise treated to filter out this energy. But in all cases, radiation protection eyeglasses for a wearer requiring corrective lenses must have filter lenses having the same optical properties as those of the wearer""s regular prescription eyeglasses.
The term filter lens as used herein in conjunction with a clip-on accessory is not limited to a lens having radiation filtration properties. It includes a lens having optical properties so that when this filter lens is placed before an optical lens of eyeglasses, it then combines therewith to form a compound lens for visual correction.
Prescription eyeglasses must be specially tailored to meet the visual requirements of its wearer and such eyeglasses are therefore costly. Should the wearer also require prescription radiation protection glasses, he is then faced with additional heavy costs.
But that is not the only drawback, for should the wearer have occasion in the course of a day to require both his regular prescription eyeglasses and his special prescription radiation protection glasses, then it becomes necessary for him to switch from one to the other and to pocket the glasses not then in use.
A significant advantage of a clip-on which converts a regular pair of eyeglasses to function as radiation-protection glasses is that when the clip-on is mounted on the eyeglasses, there is then nothing that has to be pocketed.
As shown in U.S. Pat. No. 5,889,574, a typical clip-on consists simply of a pair of rimless non-optical filter lenses joined together by a bridge, the lenses having clips anchored thereon adapted to engage the frame of eyeglasses to mount the clip-ons on the glasses. In this patent the clips are attached to the filter lenses by screws.
The use of screws in eyeglasses is commonplace, screws being included in the temple piece hinge as well as in the frame to hold the optical lenses in place. With continued use, it is not an uncommon experience for a tiny screw to turn out its socket and to be misplaced, thereby disabling the eyeglasses. This is also the problem with screws which hold clips onto the lens of a clip-on, for with continued use, the clips may become unscrewed.
A significant aspect of a clip in accordance with the invention is that no screws are required to anchor the clips on the filter lenses of the clip-on, hence there is no unscrewing problem.
U.S. Pat. No. 6,234,628 shows a pair of clip-on sunglasses whose lenses are in a frame having L-shaped plastic prongs to couple the clip-on onto the frame of spectacles. These prongs are not attached to rimless lenses as in a clip-on in accordance with the invention.
U.S. Pat. No. 5,724,118 shows a clip-on having lenses mounted in rings to which hooks are cemented or welded for connecting the clip onto the frame of spectacles. A coupling clip in accordance with the invention is not welded or cemented to the lenses.
U.S. Pat. No. 6,089,706 shows a clip-on whose lenses are held in a wire frame. The wire goes through hooks to attach the clip-on to the frame of eyeglasses. Hence it is the frame wire that holds the coupling clips in place, a very different arrangement from the plug-anchored coupling clips of the present invention.
U.S. Pat. No. 6,254,232 shows spring-biased clamping arms which act to clamp a clip onto the frame of eyeglasses. This is a far cry from the present arrangement.
U.S. Pat. No. 6,116,731 effects a connection between sunglasses and optical eyeglasses by means of plug-in projections. Along similar lines are the projections shown in U.S. Pat. No. 6,196,679. But these projections are not in the manner of the present invention associated with a hook that engages the margin of a filter lens to prevent the clip from detaching therefrom.
U.S. Pat. No. 5,694,192 discloses a clip-on whose coupling clips are joined to lenses by a tension thread, not by anchoring plugs. U.S. Pat. No. 6,244,704 welds clips 13A and 14A onto the lenses of a clip-on.
In view of the foregoing, the main object of this invention is to provide a clip-on for a pair of eyeglasses, the clip-on having filter lenses in which clips are anchored to mount the clip-on onto the frame of the eyeglasses, which clips are capable of withstanding the stresses arising from repeated use of the clip-on without becoming detached from the filter lenses. In those instances where the eyeglasses are rimless, that is one whose lenses are not mounted in a frame, then the clips are anchored onto the margin of these lenses.
Among the significant advantages of the invention are the following:
A. No screws are used to hold together the components of the clip-on, hence there is no problem of screw loosening.
B. The clips are readily attachable to the filter lenses of the clip-on thereby simplifying manufacturing procedures.
C. The clips may be mass-produced at relatively low cost.
More particularly an object of this invention is to provide a clip-on which is coupled to the margin of a filter lens at a first position displaced inwardly from the edge of the lens and at a second position adjacent the edge, which couplings act to resist detachment of the clip.
Briefly stated, these objects are accomplished by a clip-on mountable onto the frame of eyeglasses having a pair of optical-visual-correction lenses. The clip-on is provided with a pair of filter lenses held together by a bridge, the filter lenses registering with the optical lenses to convert the eyeglasses into radiation-protection glasses such as sunglasses. Anchored on the margin of each filter lens is at least one clip having a ledge at one end which supports the margin of the lens and an arm at the other end that curves over the frame of the corresponding optical lens to retain the clip-on. Intermediate the ends of the clip on the leg thereof is a transverse hook which engages the margin of the filter lens to resist dislodgment of the clip.